Closed loop tuning operation with antenna switching

Abstract

A method for detecting, at a controller of an electronic device, when an antenna switch condition associated with at least one of a first antenna and a second antenna occurs, and for responding to the antenna switch condition. The electronic device is configured with the first antenna assigned to a primary antenna path and the second antenna assigned to a secondary antenna path. In response to detecting that the antenna switch condition has occurred, a first antenna switch operation is triggered. The switch operation assigns the first antenna to the secondary antenna path and the second antenna to the primary antenna path. The method further includes performing a transmission close loop tuning on the second antenna and detecting completion of the transmission close loop tuning on the second antenna. In response to detecting completion of the transmission close loop tuning, a second antenna switch operation is executed.

What is claimed is: 
     
       1. A method comprising:
 detecting, at a controller of an electronic device configured with a first antenna assigned to a primary antenna path and a second antenna assigned to a secondary antenna path, when an antenna switch condition associated with at least one of the first antenna and the second antenna occurs; 
 in response to detecting that the antenna switch condition has occurred, triggering a first antenna switch operation, which assigns the first antenna to the secondary antenna path and the second antenna to the primary antenna path; 
 performing a transmission close loop tuning on the second antenna, wherein during the transmission close loop tuning, a tuner tunes second antenna, enabling second antenna to converge to a new optimum tune state; 
 detecting completion of the transmission close loop tuning on the second antenna; and 
 in response to detecting completion of the transmission close loop tuning, where the second antenna reaches the new optimum tune state, executing a second antenna switch operation, which re-assigns the first antenna to the primary antenna path and the second antenna to the secondary antenna path. 
 
     
     
       2. The method of  claim 1 , wherein:
 the antenna switch condition includes an expiration of a pre-defined time period associated with an amount of time a received signal is on the secondary antenna path. 
 
     
     
       3. The method of  claim 2 , further comprising:
 establishing a timer having the pre-defined time period; and 
 tracking a time to expiration of the pre-defined time period. 
 
     
     
       4. The method of  claim 2 , further comprising:
 initiating the timer in response to the first antenna being assigned to the primary antenna path and the second antenna being assigned to the secondary antenna path; 
 monitoring an elapsed time relative to the pre-defined time period; and 
 triggering the first antenna switch operation, in response to detecting the expiration of the pre-defined time period. 
 
     
     
       5. The method of  claim 2 , further comprising:
 in response to detecting the first antenna switch operation before expiration of the pre-defined time period, reinitiating the timer. 
 
     
     
       6. The method of  claim 1 , wherein:
 the antenna switch condition is associated with detection of a power delta associated with the first antenna and second antenna; and 
 the method further comprises:
 determining a variation in the power delta over a predetermined period of time; 
 identifying when the variation in the power delta exceeds a predetermined power delta variation threshold; and 
 triggering the first antenna switch operation, in response to the variation in the power delta being greater than the predetermined power delta variation threshold. 
 
 
     
     
       7. The method of  claim 6 , further comprising:
 identifying when the first antenna is assigned to the primary antenna path; and 
 in response to the first antenna being assigned to the primary antenna path, recording a primary receiver power signal level and a secondary receiver power signal level for use in a subsequent calculation of the power delta. 
 
     
     
       8. The method of  claim 1 , further comprising:
 recording a first closed loop metric in response to execution of the first antenna switch operation; 
 recording a second closed loop metric subsequent to detecting completion of the transmission close loop tuning on the second antenna; 
 calculating a difference between the second closed loop metric and the first closed loop metric; and 
 in response to the calculated difference of the second closed loop metric and the first closed loop metric being less than a predetermined hysteresis threshold, increasing a time span before triggering a subsequent execution of the first antenna switch operation by adding a time delay to postpone the subsequent execution of the first antenna switch operation, where the time delay is a calculated hysteresis time delay. 
 
     
     
       9. The method of  claim 8 , wherein:
 the first closed loop metric and second closed loop metric are each one closed loop metric from among multiple closed loop metrics comprising: an input return loss, a matching network power loss, and a predetermined metric for calculating a preferred tune state. 
 
     
     
       10. A device comprising:
 a modem; 
 a tuning circuit; 
 a first tuner and a second tuner coupled to the tuning circuit and respectively coupled to a first antenna and a second antenna; 
 a tuner controller communicatively coupled to the modem and to the tuning circuit and which includes a control module comprising a plurality of algorithms that configure the tuning circuit to:
 detect when an antenna switch condition, from among multiple antenna switch conditions, is detected; 
 trigger the first tuner and the second tuner to perform a first antenna switch operation in which the first antenna and the second antenna switch antenna paths; and 
 perform a transmission close loop tuning on one of the first and the second antenna before executing a second antenna switch operation to re-assign the antenna paths to the first antenna and the second antenna, wherein during the transmission close loop tuning, a tuner tunes second antenna, enabling second antenna to converge to a new optimum tune state; 
 detect completion of the transmission close loop tuning on the second antenna; and 
 in response to detecting completion of the transmission close loop tuning, where the second antenna reaches the new optimum tune state, execute a second antenna switch operation, which re-assigns the first antenna to the primary antenna path and the second antenna to the secondary antenna path. 
 
 
     
     
       11. The device of  claim 10 , wherein:
 the first antenna is initially assigned on a primary transmit/receive (TX/RX 1 ) antenna path as the primary antenna path and the second antenna is initially assigned to a RX 2  antenna path as the secondary antenna path; and 
 the antenna paths comprise a primary antenna path associated with a transmit signal and a first receive signal and a secondary antenna path associated with a second receive signal. 
 
     
     
       12. The device of  claim 10 , wherein the antenna switch condition includes an expiration of a pre-defined time period associated with an amount of time the second receive signal is on the secondary antenna path. 
     
     
       13. The device of  claim 12 , further comprising a timer that is initiated when a period of time equal to a convergence time of a transmission closed loop tuning algorithm on the secondary antenna path has expired. 
     
     
       14. The device of  claim 10 , wherein the antenna switch condition is associated with detection of an antenna power delta variation value of the first antenna and second antenna, when the antenna power delta variation value is an absolute value of a difference between a first receive signal power level variation and a second receive signal power level variation, where the first receive signal power level variation and the second receive signal power level variation are measured at a first time when an antenna switch is detected and at a predetermined second time subsequent to the first time when the antenna switch is detected. 
     
     
       15. The device of  claim 10 , wherein the antenna switch condition is associated with a delta value determined by a loading change detected at an external sensor, when the delta value is defined by an absolute value of a difference between a first load measurement at the external sensor and a second load measurement at the external sensor, where the first load measurement is identified at a first time when an antenna switch is detected and the second load measurement is identified at a predetermined second time, subsequent to the antenna switch. 
     
     
       16. The device of  claim 10 , wherein a first closed loop metric and a second closed loop metric are compared to a pre-defined metric threshold to determine when tuning of the first antenna should be delayed. 
     
     
       17. The device of  claim 16 , wherein the first closed loop metric and the second closed loop metric are a closed loop metric from among a group of metrics comprising:
 an input return loss, a matching network power loss, and a pre-defined metric. 
 
     
     
       18. A computer program product comprising:
 a computer readable storage device; and 
 program code on the computer readable storage device that when executed within a processor associated with a dual antenna communication device that is configured with a first antenna assigned to a primary antenna path and a second antenna assigned to a secondary antenna path, the program code enables the dual antenna communication device to provide functionality of:
 detecting, at a controller of the dual antenna communication device, when an antenna switch condition associated with at least one of the first antenna and the second antenna occurs; 
 in response to detecting that the antenna switch condition has occurred:
 triggering a first antenna switch operation, which assigns the first antenna to the secondary antenna path and the second antenna to the primary antenna path; 
 performing a transmission close loop tuning on the second antenna wherein during the transmission close loop tuning, a tuner tunes second antenna, enabling second antenna to converge to a new optimum tune state; 
 detecting completion of the transmission close loop tuning on the second antenna; and 
 in response to detecting completion of the transmission close loop tuning, where the second antenna reaches the new optimum tune state, executing a second antenna switch operation which re-assigns the first antenna to the primary antenna path and the second antenna to the secondary antenna path. 
 
 
 
     
     
       19. The computer program product of  claim 18 , wherein the antenna switch condition comprises at least one of:
 an expiration of a pre-defined time period when a timer, having the pre-defined time period associated with an amount of time a secondary receive signal is on the secondary antenna path, is established; 
 a detection of a power delta variation associated with the first antenna and second antenna, and which power delta variation is greater than a predetermined power delta variation threshold; and 
 an indicator event from among a universal serial bus input, an auxiliary cable input, a capacitive sensor input, and an infrared proximity detection input. 
 
     
     
       20. The computer program product of  claim 18 , the program code further comprising program code that enables the device to provide the functionality of:
 recording a first closed loop metric, from among multiple closed loop metrics, in response to execution of the first antenna switch operation; 
 recording a second closed loop metric, from among multiple closed loop metrics, subsequent to detecting completion of the transmission close loop tuning on the first antenna; 
 calculating a difference between the second closed loop metric and the first closed loop metric; and 
 in response to the calculated difference of the second closed loop metric and the first closed loop metric being less than a predetermined hysteresis threshold, increasing a time span before triggering a subsequent execution of the first antenna switch operation by adding a time delay to postpone the subsequent execution of the first antenna switch operation, where the time delay is a calculated hysteresis time delay.